U.S. Secretary of State Rex Tillerson and Russian Foreign Minister Sergei Lavrov have met in New York ahead of the opening of the United Nations General Assembly, with Ukraine and Syria key topics of discussion, officials said.

The U.S. State Department earlier had said that Tillerson would travel to the Russian UN mission to meet with his counterpart on September 17.

Department spokeswoman Heather Nauert after the session said in a statement that the diplomats "met this evening in New York on the sidelines of the United Nations General Assembly."

"The two recommitted to deconflicting military operations in Syria, reducing the violence, and creating the conditions for the Geneva process to move forward," she said.

Russian Foreign Ministry spokeswoman Maria Zakharova said the meeting covered the crisis in Syria, the conflict in eastern Ukraine, and "Middle East" issues.

Tillerson left the talks without speaking to reporters.

The meeting came at what Tillerson has called a "historic" low in post-Cold War relations between Russia and the United States, marred by tit-for-tat reductions to each country's diplomatic missions.

The United States has imposed sanctions on Moscow for what U.S. intelligence agencies say was widespread Russian interference in the 2016 U.S. presidential election.

Sanctions are also in place against Russia for its activities in Ukraine, including the annexation of the Crimean Peninsula and support for separatists in eastern Ukraine.

The conflict in eastern Ukraine between Kyiv's forces and Russia-backed separatists has killed more than 10,000 people since it erupted in April 2014.

Recent discussions have centered on the possibility of sending UN peacekeepers to eastern Ukraine, although the United States and Kyiv have said they do not want the deployment to cement a division of the country.

Washington and Moscow are at loggerheads as well in Syria, where Russia supports President Bashar al-Assad while the United States backs rebels fighting the government.

The U.S.-led coalition battling Islamic State (IS) militants in the war-torn country said the Russian military on September 16 struck forces backed by Washington, injuring several allied fighters. Russia denied the allegations.

UN-sponsored talks are being held in Geneva in search of a political solution to end the Syrian civil war. Separate talks are being conducted in the Kazakh capital, Astana -- sponsored by Russia, Iran, and Turkey -- to deal with cease-fire and other battlefield matters.

It was not immediately reported if the discussions involved the crisis over North Korea's continued defiance of UN resolutions against its testing of nuclear weapons and ballistic missiles. Russia and China have pushed back against U.S. demands for the two to take "direct action" against Pyongyang.

Lavrov is expected on September 21 to speak in front of the General Assembly, which runs through September 25.

Russian President Vladimir Putin will not attend the General Assembly. U.S. President Donald Trump is scheduled to speak before the 193-member UN on September 19.